Health Media Ltd

A team led by Dr Philip Holland from the Department of Paediatrics at Leeds General Infirmary studied 34 children aged between 7 and 13 who wet the bed at least four times a week. The children were patients at a specialist clinic and had been treated with a synthetic version of the hormone vasopressin, which suppresses urine production. Researchers gave the children a neuro-psychological test, known as the Rey-Osterrieth test, which assessed their planning and organisational skills as well as their problem-solving abilities. The children had to copy and redraw a linear image from memory. Their ability to accurately reproduce the figure was scored according to their number of "boundary" errors, such as incorrect spacing, or missing out various lines and shapes. Those children who did not respond to vasopressin treatment made significantly more errors than those who did respond. Out of the 34 children, 11 made three or more errors in the copy and memory tasks. None of them had responded to the synthetic vasopressin. The researchers say that controlling the bladder at night requires the correct nerve signalling between the visual cortex, the pituitary gland and the bladder. This ensures that vasopressin is released at night as part of the natural body clock and that people wake up if the bladder becomes full. The team suggest that unspecified factors before and after birth, at a crucial point of nerve development, affect the growth of nerves in the parts of the brain that regulate urine production at night. The research is published in the Archives of Disease in Childhood.